The Evolution of the Light Car

A chronology of the beginning of the light car.  The innovations that were incorporated in the motorcar.

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The first wheels
500BC. British Iron Age chariots, their wheel hubs and spokes turned on a rotary lathe.

Invention of the road spring
1665. a friend of Samuel Pepys named Colonel Blunt invented the steel elliptical road spring. His work was continued by a Lambeth coach maker Obadiah Elliot who patented the elliptical spring.

The car boot
On a stagecoach, passenger’s luggage was carried at the back of the coach in a box on which the guard stood, hence The Boot, the name still used in the modern car.

Rubber Tyres
1795 Prince Orloff presented a rubber tyred carriage to Zarina Catharine 2nd of Russia.
1888 John Boyd Dunlop re-invents the Pneumatic Tyre.
1895 Michelin tested their special Pneumatic Tyres in the Paris Bordeaux race.

The First Steam Transport
1767 Nicolas Joseph Cugnot in France introduced the first steam transport, having constructed a wooden carriage with a big round boiler on the front. Steam was fed from the boiler to a 2-cylinder steam engine. The carriage was 24ft (7.3m) long, 7ft 8 inches (2.3m) wide. The maximum speed of the carriage was 2.5 miles per hour (4Km).It had to stop every 15minutes to top up the boiler and refuel. It could carry four passengers and was steered using a tiller.

One of these machines is preserved in Paris.

In England the famous engineer James Watt and his assistant William Murdock experimented with steam propulsion. However it was left to the brilliant Cornish engineer Richard Trevithick to produce the first successful steam carriage in 1801. Called the “Puffing Devil”, it was tested in Camborne in 1801 when it ran at 9 miles per hour {14.4km/hr}. A boiler explosion destroyed this carriage; it was rumoured it was parked outside a public house at the time! By 1803 Trevithick had built another machine and this carriage could travel faster than a horse and cart. Why Richard Trevithick did not continue with his work we shall never know.

It was left to another Cornishman, Sir Goldsworthy Gurney, a surgeon born at Treator, near Padstow, to produce a successful Steam Horseless Carriage. In 1827 he patented a steam driven road locomotive.  The flue for the fire was at the back of the carriage and it burned either charcoal or coke to stop smoking.  A 12 horsepower steam engine was fed superheated steam from a 40-tube boiler.  The engine drove the back wheels. At the request of the war office the machine was road tested and travelled from London to Bath and back at an average speed of 15mph.  It was never used by the government but was used in the West Country.

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In parallel with Gurney’s work Walter Hancock of Stratford London put on the road a series of highly successful steam carriages. Mechanised transport had arrived.

The internal combustion engine
Internal combustion engine describes an engine where the combustion of the fuel is inside the engine. The first of these were gas engines.  In 1794 a chap called Street suggested gasses for fuel. In 1823 Samuel Brown invented a coal gas engine, which he fitted to a road carriage. The action was based on a pair of pistons working in cylinders. The pistons were forced up by the pressure of a gas flame and returned downwards by atmospheric pressure.

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Brown's apparatus was too clumsy to work correctly and the first gas engine was evolved by the Frenchman Lenoir in 1860.  His engine used a mixture of gas and air fired by an electric spark to move the piston in the cylinder. In 1862 it was another French engineer Beau De Rochas that developed the theory of the modern internal combustion engine, He arranged a method of compressing the mixture before it was fired.

Working at the same time was the German Engineer Doktor N A Otto.  He designed a successful coal-gas engine (the Otto Cycle), based on de Roche’s principles.  He had researched this work in a small factory near Cologne in1863.  He employed a technical Director, Gottlieb Daimler.  In 1882 Daimler branched out on his own at a place called Cannstatt and it was here that he developed the first lightweight internal combustion engine that used petroleum vapour fuel. However his was not the first engine designed to work on petrol vapour. In 1879 an Austrian named Siegfried Narkus fitted a small petroleum-vapour engine to a two-wheeled handcart.

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Daimler’s engine was much lighter than the previous gas engines; the gas engines developed 1 hp for every 300lbs weight. At a crank speed of 250rpm.

Daimler’s engine was capable of running at up to 800rpm and it developed 1 hp for every 90 lbs weight.

In 1885 Carl Benz built his first car using an engine of his own design.

Daimler used hot-tube ignition for his machines while Benz used electric spark.

1890 Panard and Lavassor started producing cars using Daimler engines. These cars were of fundamental importance as they originated the formula of placing the engine in the front under a bonnet.

In the 1890’s the car was born and production started in Western Europe and the United States.

The Primitives
These were a cocktail of designs basic 3 or 4-wheeled carriages, with an engine and tiller steering. In this short article there is not sufficient space to describe how each evolved.

Henry Ford in 1896 produced one of the first small cars; it had a simple open chassis frame supported on four tangent-spoked wheels fitted with small pneumatic tyres. The front axle was supported by a full elliptical spring and incorporated tiller-controlled Ackerman steering. The 2-cylinder engine produced 3 hp.

light car 8To continue the next major invention that effected the light car development was the De Dion-Bouton engine. Ten years after Daimler’s invention of the medium speed engine there occurred another advance of fundamental importance in engine design. Two Frenchman Count Albert de Dion and Georges Bouton developed a lightweight engine using Daimler’s principles. This engine weighed just 40lbs and produced ½ hp at 1500rpm. Continual development of this engine continued so that by 1902 it produced 8hp for an average weight of 25lbs.

These engines were produced in increasing numbers at the De Dion-Bouton works at Puteaux and also under licence in England Belgium, Germany and America.

The impetus which this highly practical power unit gave to the young motor industry in general was of the greatest importance.

The Cycle Car
light car 10From the photo it can be seen that the by 1909 the Austin Voiturette were taking on the form of the motorcar as we would recognise it.

1910 saw the development of the cycle car. These cars had evolved from their predecessors the Tricars, Quadricars and Voiturettes.

From a primitive stage of development these vehicles could now embark on long journeys. Their engines were robust; ignition systems were reliable and efficient practical spray carburettors were in production.

The design of these light cars was based on lightweight motorcycle components rather than the heavier motorcar. 

On the 14th of December 1912 at a meeting of the Federation International des clubs Motto Cyclist, it was decided there should be an international classification of cycle-cars. This was accepted by all nations. 

This type of car introduced motoring for the common citizen.  These cars were able to be run for about a penny per mile and cost between £60 & £200 pounds. 

The next big event in world history was the First World War when all production of cars for civilian use stopped. 

From 1919 to1929, the decade after the First World War was one of the most important in the evolution of the light car. It was notable for the development of the Ultra-light car as distinct from the cycle car. 

In 1922 Herbert Austin designed a miniature car that was virtually a scaled down large car. Six prototypes were built with 696cc.  Four-cylinder water-cooled engines. This engine developed 10 bhp at 2400 rpm and weighed 7 cwt. (356 kg), giving a power to weight ratio of 28.6 bhp/ton.

One of these prototypes was presented to the Science Museum in 1953. Full commercial production of the Austin Seven began in 1923 but with an improved engine of 747.5 c.c. 

Improved models of the Austin seven appeared from year to year as demand for it increased but the essential design remained unaltered. 

The first A7 Ruby had a 2 bearing crankshaft like its earlier brothers and sisters: the engine had a compression ratio of 5.4 to 1, it developed 13.5 bhp at 3500 rpm.  As the weight had been increased to 1385lb, this gave a lower power to weight ratio of just 21.8 bhp/ton.

By 1937 the engine had been replaced with basically the same power unit but with a centre bearing fitted in the crankcase.  The compression ratio had been increased to 6.3 to 1, and the engine now developed 17hp. This extra power brought the  power to weight ratio back up to 27.5 bhp/ton.  

In practical tests matching the 1937 Ruby to the earlier cars, the older cars appear to be much faster.  

The Austin Seven ceased production in 1938 due to public demand for a larger bodied car. This was supplied by the 900 cc Austin Big Seven which developed 25 bhp at 4000 rpm, launched as a four-door (Sixlite) version in July 1937 and two-door (Forlite) in March 1938. 

Here was must end our end our story of the evolution of the light car.

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To finish, more Chronology
Coolant- 1859 Ethylene Glycol invented by the French chemist Charles Wurtz. It was not put into mass production until 1937.

Wheels-  Up to 1914 wooden spoked or wire spoked fix wheels were used.

1914 saw the introduction of detachable wheels  of the Rudge-Whitworth or Riley type used.

Carburetion- 1893 Float feed spray carburettor devised by Wilhem Maybach. This ensured the fuel-air mixture remained constant.
 
Ignition - Robert Bosch(1861-1942) was the first to make and patent a reliable Magneto in 1902.

Nikola Tesla (1856-1943) worked on the generation of high voltage using coils.

Kettering’s high-tension coil and battery system became widespread in the 1920’s.

Bodywork (1925/1930) - In order to cut down on body weight, many light cars used leather flexible covering.

Paintwork - Early cars used paint and varnish, this was good for about 12000 miles. 

In 1924 Du Pont introduced cellulose and by 1930 this was universally adopted.

Petrol - 10th January 1928, Pratt’s motor oils introduced leaded petrol from America.

This article, written by Ian Leaver, appeared in Focus in three parts in Jan 2010 pp12-13; Feb 2010, pp12-14 and Mar 2010 pp16-17.

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